If you were near 40 or older it can be "presbyopia", if you're much younger it could be latent hyperopia (farsighted) or "convergece insufficiency" There are other causes elated to health such as high blood pressure or hi/low blood sugar.
Suggest you start by seening an Eye MD ophthalmologist, find one near you at www.geteyesmart.org
Ok, you mentioned high blood sugar. I drank upwards of a half gallon of orange juice that morning for no reason other than I was really thirsty and it was there. Could that offset my blood sugar? I weigh about 135lbs. Could that be the cause?
No, I'm talking about severe undiagnosed diabetes which would have increased urination, severe fatigue, weight loss.